A062081 Group the even numbers as (2,4), (6,8,10,12), (14,16,18,20,22,24), (26,28,30,32,34,36,38,40), ... then a(n) = LCM of the n-th group.

4, 120, 55440, 42325920, 7210803600, 43790142876480, 6338767304469600, 659267412349963697280, 1688424674909818263818400, 2043724034861836818744052800, 9347568224452825219277416992000

Offset

1,1

Links

Harry J. Smith, Table of n, a(n) for n = 1..100

Example

a(2) = lcm(6,8,10,12) = 120.

Mathematica

Table[LCM@@(2*Range[1-n+n^2, n+n^2]), {n, 15}] (* Harvey P. Dale, Jul 18 2015 *)
Module[{nn=11, tl}, tl=TakeList[Range[2, 2nn+(2nn)^2, 2], Range[2, 2nn, 2]]; LCM@@@ tl] (* Harvey P. Dale, Jan 29 2023 *)

Prog

(PARI) for(n=1, 20, p=1:forstep(k=2*(n^2-n+1), 2*(n^2+n), 2, p=lcm(p, k)):print1(p", "))
(PARI) { for (n=1, 100, a=b=2*n^2 - 2*n + 2; for (k=1, 2*n - 1, a=lcm(a, b + 2*k)); write("b062081.txt", n, " ", a) ) } \\ Harry J. Smith, Jul 31 2009

Crossrefs

Sequence in context: A006607 A286757 A239187 * A374723 A053881 A075114

Adjacent sequences: A062078 A062079 A062080 * A062082 A062083 A062084

Keyword

nonn

Author

Amarnath Murthy, Jun 15 2001

Extensions

Corrected and extended by Ralf Stephan, Mar 20 2003

Status

approved